Botrytis Management in Cut Roses Melissa Muoz, James E. Faust & - PowerPoint PPT Presentation

Botrytis Management in Cut Roses Melissa Muñoz, James E. Faust & Guido Schnabel

Ph.D. Horticulture Ph.D. Plant pathology Floriculture Physiology • Integrated management of diseases • • Effects of environmental and cultural factors on • Botrytis control in strawberries and blackberries the production of ornamental greenhouse Fungicide resistance mechanisms • crops Decision-support models and smart-phone apps • • Botrytis found on pansy flowers at a Florida to reduce and better time pesticide applications nursery that was resistant to all of the main fungicides used to control Botrytis

Context BBC news

The problem • Botrytis cinerea: ü Ubiquitous ü 200 species plant hosts ü Necrotrophic • Roses: ü Reduction in the postharvest quality, leading to substantial economic loss by growers and wholesalers

The problem 400x 400x Ø Leaf wetness Ø 93% Relative humidity Ø 15-25ºC Optimum . 0ºC to 35.5ºC

Dis Diseas ase t trian iangle le Susceptible host Virulent pathogen Conducive environment

To evaluate weather conditions in commercial greenhouses and their relationship with Botrytis occurrence

Co Context • SAS - Strawberry Advisory System: is a web site, and smarth-phone app that provides an easy way for strawberry growers in Florida to track and forecast risk levels for Botrytis and anthracnose fruit rot diseases. It also provides fungicide application recommendations and allows growers to receive alerts for selected weather stations via push notifications.

Installation of weather stations • Solar radiation (W/m 2 ) • Leaf wetness (min) • Air temperature (°C) • Relative humidity (%) • Dew point (°C) • Leaf temperature (°C) • Soil temperature (°C) • Electrical conductivity (mS/cm) • Water content of soil media (%) • Wind speed (m/s) • Wind direction

Typical daily weather pattern 500 400 Solar radiation 300 (W/m 2 ) 200 100 0 22.5 Air temperature 20.0 ( o C) 17.5 15.0 12.5 10.0 90 Relative humidity 80 (%) 70 60 50 60 Leaf wetness 50 40 (min/h) 30 20 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 : : : : : : : : : : : : : : : : : : : : : : : : 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 0 1 2 3 4 5 1 1 1 1 1 1 1 1 1 1 2 2 2 2 Hour

BOTRYTIS RISK MODEL DEVELOPMENT

Botrytis infection risk Le Leaf af wetn tness Temperature Te Infect In ection risk Month Date Da Risk Ri ( o C) (h (h) C) (%) %) 2/20/17 7.5 11.4 February 6.3 No 2/21/17 0.0 16.9 February 1.4 No 3/17/17 12.5 11.6 March 16.9 No 4/15/17 April 12.5 11.3 15.9 No 4/17/17 April 24.0 14.3 88.1 High 5/29/17 May 11.5 11.6 14.2 No 5/30/17 May 10.6 11.9 12.5 No 6/9/17 Jun 19 14.3 67.7 Mid 6/14/17 Jun 15.3 13.2 36.9 Low 6/15/17 Jun 8.0 12.8 8.5 No 6/16/17 Jun 24.0 15.4 91.5 High 6/29/17 Jun 13.5 11.1 17.9 no 6/30/17 Jun 17.8 13.2 51.8 Mid 7/1/17 July 20.1 15.0 76.6 High 7/15/17 July 14.5 11.7 24.5 No 7/28/17 July 15.25 11.9 29 No 8/17/17 August 14.5 11.7 24.9 No 9/02/17 September 14.8 11.7 25.6 No 9/03/17 September 24 12.2 76 High

Pr Predicte ted vs. real eal Botr trytis tis inc incidenc idence e values alues 100 90 80 70 Incidence (%) 60 50 40 30 20 10 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 Week Actual Botrytis Incidence Predicted Botrytis Incidence

• The disease risk model has value and can become as part of an integrate management program of Botrytis • Weather stations are a tool that may improve timing for fungicide applications

To evaluate Botrytis spores density in commercial greenhouses and their relation to cultural practices

Installation of spore traps

Counting spores process 400 x 100 x

Spores density

Spores density

Spores density

Cultural practices Harvesting Botrytis removal Thermo-fogging • • • Pinching Dead stems pruning Supplementary • • • Sweeping floors* Dead stems removal watering of beds • • Blowing (debris Weeding PGRs application • • • removal)* Drenching Cutting zone cleaning • • Manual debris Fungicide spray Plastic change • • • removal application Fertilizer containers • Downy mildew Pesticide spray change • • removal application

The number and type of cultural practices have an effect on Botrytis spore density

To determine Botrytis severity in different rose tissues from commercial shipments

Assessi ssessing g Botrytis s Occu ccurren ence ce & Se Sever erity y on Commer mmerci cial Rose se Sh Shipmen ments • South American Study : • One Farm • 2 Greenhouses • One Susceptible Variety: Orange Crush • Six Shipments • Geographical Study : • Four Locations: Ecuador, Africa, Colombia; Guatemala or Mexico • Four Shipments

Samp Sa mple Co Collection and Processing Outer Petals Stems Mid Petals Inner Petals Ovary and Stamens Sepals Leaves

Botrytis occurrence in different plant tissue: South America Study Results: Stems Stamens & 13.2% ovary 5.3% Sepals 7.9% 73.7% Petals Petals are the most susceptible tissue

Botrytis occurrence in different plant tissue: South America Study Results: Stems Stamens & 13.2% Inner ovary 13.2% 5.3% Sepals 7.9% Mid 26.3% Outer Petals 34.2% A significant portion of the infection occurs in tissues that are not exposed (Mid and inner petals, stamens and ovary)

To assess fungicide resistance profiles in Botrytis isolates from commercial cut roses

Context • Resistencia: refers to an acquired, heritable reduction in sensitivity of a fungus to a specific anti-fungal agent (or fungicide). • FRAC (Fungicide resistance action committee): Group together the fungicides that are in risk of cross resistance development, because have a similar mode of action

Fungic Fung icide ide Res esis istanc ance e Profiles iles FUNGICIDE RESISTANCE PROFILES: 11 FUNGICIDES THAT BELONG TO 7 CHEMICAL CLASSES (FRAC) Outer Petals South America Study Control 49 Single spore isolates FRAC 9: Cyprodinil Stems Mid Petals FRAC 12: Fludioxonil Geographical Study 58 Single spore isolates FRAC 17: Fenhexamid Inner Petals FRAC 2: Iprodione Ovary and Stamens FRAC 1: Thiophanate-methyl Sepals FRAC 19: Polyoxin D Leaves FRAC 7: Boscalid FRAC 7: Fluopyram FRAC 7: Penthiopyrad FRAC 7: Isofetamid FRAC 7: Pidiflumetophen

(S (South Amer Fung Fungic Resistant Isoates (%) Resistant Isolates (%) 100 100 20 40 60 80 20 40 60 80 0 0 FRAC 1 FRAC 1 FRAC 2 icide FRAC 2 Shipment 4 n=13 FRAC 9 FRAC 9 meric ide Res FRAC 7 Shipment 1 n=4 FRAC 7 FRAC 17 FRAC 17 ica FRAC 7 FRAC 7 a Study) FRAC 7 FRAC 7 esis FRAC 7 FRAC 7 FRAC 12 istan FRAC 12 FRAC 7 FRAC 7 FRAC 19 ant FRAC 19 Resistant Isolate t Is Resistant Isolates (%) Resistant Isolates (%) 100 Isola 20 40 60 80 100.0 0 20.0 40.0 60.0 80.0 0.0 FRAC 1 lates FRAC 1 FRAC 2 FRAC 2 FRAC 9 FRAC 9 FRAC 7 es: 6 Shipm Shipment 5 n=7 Shipment 2 n=11 FRAC 7 FRAC 17 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 12 FRAC 7 hipmen FRAC 7 Sensitive Isolate FRAC 19 FRAC 19 Resistant Isolates (%) Resistant Isolates (%) 100.0 20.0 40.0 60.0 80.0 100.0 0.0 20.0 40.0 60.0 80.0 0.0 ents FRAC 1 FRAC 1 FRAC 2 ts FRAC 2 FRAC 9 FRAC 9 Shipment 3 n=5 Shipment 6 n=9 FRAC 7 FRAC 7 FRAC 17 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 12 FRAC 7 FRAC 7 FRAC 19 FRAC 19

Fung Fungic icide ide Res esis istan ant t Is Isola lates es (So South America St Study) y) 100 Fungicides applied in the last year Resistant Isolates (%) 90 Fluxapyroxad : FRAC 7 80 Pyrimethanil: FRAC 9 70 Famoxadone: FRAC 11 60 Azoxystrobin: FRAC 11 50 Propamocarb: FRAC 28 40 Fluopicolide: FRAC 43 30 Cymoxanil: FRAC 27 20 Tebuconazole: FRAC 3 10 Fluazinam: FRAC 29 0 Prochloraz: Multisite Captan: Multisite Iminoctadine: Multisite Zinc diethyldithiocarbamate: Protectant Resistant Isolate Sensitive Isolate

Fung Fungic icide ide Res esis istan ant t Is Isola lates es (Geogr (G ographical S Study) y) Ecuador n=23 Colombia n=4 Guatemala n=4 100 100 100 Resistant isolates (%) Resistant isolates (%) Resistant isolates (%) 90 90 90 80 80 80 70 70 70 60 60 60 50 50 50 40 40 40 30 30 30 20 20 20 10 10 10 0 0 0 FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC 1 9 2 17 7 7 7: 12 7 7 19 1 9 2 17 7 7 7: 12 7 7 19 1 9 2 17 7 7 7: 12 7 7 19 Africa n=26 Mexico n=2 100 100 Resistant isolates(%) Resistant isolates (%) 90 90 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC FRAC 1 FRAC 9 FRAC 2 FRAC 17 FRAC 7 FRAC 7 FRAC 7: FRAC 12 FRAC 7 FRAC 7 FRAC 19 1 9 2 17 7 7 7: 12 7 7 19 Aislamientos resistentes Aislamientos sensibles